Belt-platen abrading machine



Dec. 1, 1970 R. 1.. SCHALLER 3,543,443

BELTPLATEN ABRADING MACHINE Filed on. 16, 1968 4 SheetsSheet 1 INVENTOR.ROBERT L. SCHALLER.

BY W,

Dec. 1, 1970 R. L. SCHALLER 3543,44

BELT-PLATEN ABRADING MACHINE Filed Oct. 16, 1968 4 Sheets-Sheet 2INVENTOR. ROBERT L. SCHALLER.

Dec. 1, 1970 R. L. SCHALLER BELT-PLATEN ABRADING MACHINE 4 Sheets-Sheet4 Filed Oct. 16, 1968 llllallllllllllllllr INVlz'N'IOR. L. SCHALLER.

ROBERT 3,543,448 BELT-PLATEN ABRADIN G MACHINE Robert L. Schaller,Camillus, N.Y., assignor to Sundstrand Engelberg, Inc., a corporation ofDelaware Filed Oct. 16, 1968, Ser. No. 768,022 Int. Cl. 1524b 21/12 US.Cl. 51-148 8 Claims ABSTRACT OF THE DISCLOSURE An abrading machineemploying an endless abrading belt and having a platen for backing up arun of the belt. The platen and the belt tensioning mechanism aremounted in the machine framework in such manner that stresses developedby the tensioning mechanism are not transmitted to the platen. There isalso included means operable to extend a small area of the abrading beltforwardly from the face of the platen for rapid rough grindingoperation.

BACKGROUND OF THE INVENTION In the conventional structural arrangementof belt abrading machines having a backup platen, both the platen andthe mechanism for supporting the idler roll and tensioning the belt aremounted on a common member constituting part of the machine framework.Especially, in large belt grinders employed for abrading largeworkpieces, the necessary tension applied to the belt is of considerablemagnitude, creating stresses of substantial force in the machineframework, and these forces vary during the operation of the machine.With the platen attached to the same member, or a component of the sameframe structure to which the tension mechanism is attached, thesevarying forces of substantial magnitude are transmitted to the platen,causing it to shift out of alignment, or from initial position. Thisshifting of the platen results in causing inaccuracies in the workpiecebeing abraded.

BRIEF SUMMARY OF THE INVENTION A vertically disposed heavy side plate isfixed to a base. An arbor housing is fixed in the lower portion of theside plate. The arbor for the lower drive pulley is journalled in thishousing. An idler roll supporting and tensioning mechanism, in the formof a fluid operated cylinder, is fixed to the side plate above the drivepulley. Front and rear plates are fixed to the front and rear edges ofthe side plate and, in conjunction with the side plate and a second sideplate fixed to the free edges of the front and rear plate, form a boxstructure positioned intermediate the lower drive pulley and the upperidler pulley. The front and side plates are arranged in spaced relationto the mounting of the tensioning cylinder. The platen is attached tothe front plate.

With this arrangement, forces exerted by the tensioning cylinder are nottransmitted directly to the platen. The platen is formed with atransversely extending slot intermediate its upper and lower edges andthe ends of the slot terminate inwardly from the side edges of theplaten. A bar is mounted in the slot for movement outwardly from theface of the platen to how the belt outwardly from the platen to presenta relatively small transversely extending area of the belt to aworkpiece. Upon movement of a rotating workpiece in engagement with thisarea of the belt, the reduced area of the belt effects a rapid removalof stock from the workpiece for rough grinding. After the rough grindingoperation, the bar is retracted and the belt passes over the entire flatsurface of the platen for precision grinding.

nitecl States Patent m 3,543,448 Patented Dec. 1, 1970 BRIEF DESCRIPTIONOF DRAWINGS FIG. 1 is a side elevational view of an abrading machineembodying my invention. In the view, the central portion of the machineproper is shown in section, the section corresponding to line 1--1, FIG.3.

FIG. 2 is a vertical sectional view taken on line 2-2, FIG. 1.

FIG. 3 is a transverse sectional view taken on line 33, FIG. 1.

FIG. 4 is an enlarged front elevational view of the platen, with aportion of the same broken away.

DETAILED DESCRIPTION A side plate 10 is fixedly secured, as by welding,to a plate 11 which, in turn, is fixedly secured to a base structure 12.The lower portion of the plate 10 is apertured to receive a cylindricalbearing housing 13, see FIG. 2, which is fixed to the plate as byWelding. A pulley arbor 14 is journalled in bearings 15 mounted in thehousing 13, the arbor having a portion 17 extending in a directionlaterally from the plate 10. A driving pulley 18 is fixedly secured tothe extending portion 17 of the arbor.

Vertically disposed members 20 are fixedly secured to the inner surfaceof the plate 10. The members 20 are formed in their upper and lowerportions with apertures 23 for the reception of cap screws 25 threadedinto the end plates 27 of a cylinder 28. The cylinder 28 is accordinglyvertically disposed, and the piston rod 30 has attached to its upper enda yoke 31, the leg portions of which carry bearings 33 in which isjournalled a shaft 34 carrying an upper idler roll 35. The abrading belt36 is trained over the pulleys 18, 35.

Also fixed to the inner surface of the side plate 10 is a front plate 37and a rear plate 38. These plates, like the cylinder 28, are arrangedintermediate the pulleys 18 and 35. The plates 37, 38, are arranged inspaced relation to the members 20 and cylinder 28.

A second side plate 40 is fixed, as by welding, to the opposite ends ofthe front and rear plates 37, 38, the side plates 10, 40, and the frontand rear plates 37, 38, forming a box structure, see FIG. 3, overhangingthe driving pulley 18. A platen support 41 is fixed to the front wall37, as by screws 43, extending through the support and threading intothe wall 37. The platen support 41 is also formed with threadedapertures to receive screws 45, the inner ends of which engage againstthe wall 37 and serve to adjust the spacing between the platen supportand the wall 37 for the purpose of properly aligning the support.

A platen 47 is detachably affixed to the outer face side of the support41. The platen may be afiixed to the support in a conventional mannerwherein the platen is formed with V-grooves along its upper and loweredges for the reception of clamp members 48 moved into clampingengagement with the support by screws 50. With this arrangement, theplaten is clamped snugly against the support member.

The platen 47 and the support member 41 are formed, intermediate theirends, with a transversely extending slot, the ends of which terminate ininwardly spaced relation to the side edges of the platen and support. Abar 57 is positioned in this slot for movement therein outwardly throughthe face of the platen. Stems 60 are attached to the bar 57 and extendinwardly through the support 41 and through the front wall 37. The stems60' serve as piston rods, carrying pistons 61 mounted in cylinders 63secured to the inner surface of the front wall 37, as by screws 62. Thecylinders extend inwardly and have closures 65 at their inner ends. Theclosures 65 and the bases of the cylinders are provided with O-ringpackings 67. The piston rods 60 extend through the end closures 65 andare provided with stop members 70 adjustable axially of the piston rods60 by nuts 71.

When fluid under pressure is supplied to the inner ends of the cylinders63 by line 73, the piston rods 60 and bar 57 are moved outwardly to theposition shown in FIG. 1, this movement imparting a bowed condition tothe abrasive belt 36. The limit of the outward movement of the bar 57 isdetermined by the setting of the stop members 7 on piston rods 60. Theouter surface of the bar 57 is preferably provided with wear resistingmaterial 74, such as tungsten carbide. Outward movement of bar 57results in a small area of the belt 36 being presented to the workpiece,indicated at 75, the workpiece being mounted on the spindle of a rotarywork fixture 76 driven by a motor 77, FIG. 1. Upon rotational engagementof the workpiece with the relatively small area of the belt pressedagainst the workpiece by bar 57, results in material being rapidlyremoved from the workpiece.

The rotary fixture 76 is mounted on a table 80 involving conventionalslide structures by which the table is movable on the base structure 12toward and from the abra sive belt, and also transversely thereof.

When the surface of the workpiece 75 has been rough ground, fluid issupplied to the inner ends of the cylinders 63 by line 83 to effectretraction of the bar 57 into the slots formed in the platen and theplaten support, as shown in FIG. 3. Thereupon, the workpiece may bemoved into engagement with the belt, which is then backed up by the flatand accurately adjusted platen for precision finishing of the workpiece.

An outboard bearing arm 85 is fixed to the outer surface of the sidewall 40 and carries a bearing 86 in which the outer end of the arbor 14is journalled. A plate 87 is fixed to the base plate 11 and extendsupwardly therefrom in outwardly spaced relation to the side wall 10, andis connected thereto by a plurality of transversely extending stiffeningmembers 88. The plate 87 and members '88, in conjunction with the sidewall form a column structure imparting great rigidity to the plate 10.The yoke 31 is formed with a laterally extending arm 90, the outer endof which extends through a vertical slot 91 in plate 87 and into avertical slot 92 in a plate 93 mounted for sliding movement in ways 94attached to the outer surface of the plate 87, see FIGS. 1 and 2. Ascrew shaft 95 is operatively connected to the plate 93 for moving thesame forwardly and rearwardly to swing the yoke 3-1 about the axis ofthe piston rod 30 to initially track the belt on the pulleys *18, 35.

What I claim is:

1. An abrading belt platen type abrading machine comprising a framestructure including a side plate, an arbor housingfixed in said plate,an arbor journalled in said housing with the axis of the arbor extendingnormal to said plate, said arbor having an end portion extendinglaterally from said plate, a drive pulley fixed to the extending endportion of said arbor, a cylinder mounted on said side plate, a pistonand piston rod mounted in said cylinder, said rod extending from saidcylinder in a direction away from said pulley, a yoke fixed to theextending end of said piston rod and an idler pulley journalled in saidyoke, front and rear plates fixed to said side plate and extendinglaterally therefrom intermediate said pulleys at opposite sides of ofsaid cylinder and spaced therefrom, a second side plate fixed to thefree ends of said front and rear plates, a platen fixed to the outersurface of said front plate, an abrading belt trained over said pulleyswith a run of the belt passing over said platen, and means operativelyconnected to said arbor to effect rotation of the same and said drivepulley.

2. An abrading machine as set forth in claim 1, wherein said side plateis fixedly secured to a base and extends upwardly therefrom.

3-. An abrading machine as set forth in claim 1, and including a secondside plate fixed to'the free edges of said front and rear plates, and anoutbroad bearing for the free end of said arbor attached to said secondside plate.

4. An abrading machine as set forth in claim 1, and including means fordetachably securing said platen to said front plate, and means foradjusting said platen relative to said front plate.

5. An abrading machine as set forth in claim 1, and including a platenmounting plate, means for detachably securing said mounting plate tosaid front plate, means for adjusting said mounting plate relative tosaid front plate, and means for detachably securing a platen to saidfront plate.

6. An abrading machine as set forth in claim 1, wherein said platen isformed in the surface confronting said abrading belt with a transverselyextending slot, a bar positioned in said slot and means operable to movesaid bar outwardly from said platen into engagement with said abradingbelt to effect a bowed configuration thereto.

7. An abrading machine as set forth in claim 1, wherein said platen isformed in the surface confronting said abrading belt with a transverselyextending slot, the ends of said slot terminating inwardly of the sideedges of said platen, a bar positioned in said slot, piston and cylinderstructures mounted on the inner surface of said front side wall andbeing operatively connected to said bar to effect outward movementthereof into engagement with said abrading belt to effect a bowedconfiguration thereto.

8. An abrading machine as set forth in claim 1, and including an outerplate fixed to said base and extending upwardly therefrom in outwardlyspaced relation to said first side plate, stiffening members extendingtransversely between said side plate and said outer plate and beingfixed thereto and forming a column structure.

References Cited UNITED STATES PATENTS 3,134,206 5/1964 Olton et al.51-142 3,136,096 6/1964 Hine 51142 3,451,174 6/ 1969 Schaller 51-148OTHELL M. SIMPSON, Primary Examiner

